Function RTMPSetPICMode

RTMPSetPICMode reverts from APIC mode to legacy PIC mode:

void RTMPSetPICMode(void);

All IOAPICs are disabled and the legacy i8259 interrupt controllers are reenabled. All IRQ values in the PCI config space are reset to their boot state. Nevertheless, interrupts are no longer delivered to PCI devices after this call.

It is generally not recommended to call this function. An application which has switched to APIC mode using RTMPSetAPICMode should stay in APIC mode until it is rebooted.